相关疑难解决方法(0)

我正在尝试使用iTextSharp在PDF文档的每个页面上创建一个页脚,其格式为Page#of#,跟随iText页面和书籍上的教程.虽然我一直在cb.SetFontAndSize(helv,12)上得到一个例外; - 未将对象引用设置为对象.有谁能看到这个问题？代码如下.

谢谢,罗布

public class MyPdfPageEventHelpPageNo : iTextSharp.text.pdf.PdfPageEventHelper
{
    protected PdfTemplate total;
    protected BaseFont helv;
    private bool settingFont = false;

    public override void OnOpenDocument(PdfWriter writer, Document document)
    {
        total = writer.DirectContent.CreateTemplate(100, 100);
        total.BoundingBox = new Rectangle(-20, -20, 100, 100);

        helv = BaseFont.CreateFont(BaseFont.HELVETICA, BaseFont.WINANSI, BaseFont.NOT_EMBEDDED);
    }

    public override void OnEndPage(PdfWriter writer, Document document)
    {
        PdfContentByte cb = writer.DirectContent;
        cb.SaveState();
        string text = "Page " + writer.PageNumber + " of ";
        float textBase = document.Bottom - 20;
        float textSize = 12; …